Copyright (c) 2016-present, RxJava Contributors.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is
distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
the License for the specific language governing permissions and limitations under the License.
/**
 * Copyright (c) 2016-present, RxJava Contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
 * the License for the specific language governing permissions and limitations under the License.
 */

package io.reactivex.disposables;

import java.util.concurrent.atomic.AtomicReference;

import io.reactivex.annotations.NonNull;
import io.reactivex.internal.functions.ObjectHelper;

Base class for Disposable containers that manage some other type that
has to be run when the container is disposed.
Type parameters:
<T> – the type contained/**
 * Base class for Disposable containers that manage some other type that
 * has to be run when the container is disposed.
 *
 * @param <T> the type contained
 */
abstract class ReferenceDisposable<T> extends AtomicReference<T> implements Disposable {

    private static final long serialVersionUID = 6537757548749041217L;

    ReferenceDisposable(T value) {
        super(ObjectHelper.requireNonNull(value, "value is null"));
    }

    protected abstract void onDisposed(@NonNull T value);

    @Override
    public final void dispose() {
        T value = get();
        if (value != null) {
            value = getAndSet(null);
            if (value != null) {
                onDisposed(value);
            }
        }
    }

    @Override
    public final boolean isDisposed() {
        return get() == null;
    }
}